The use of the amphetemine-like drug Qat, is reported to be institutionalized and almost universal in the Yemen Arab Republic. Existing information is contradictory and inconclusive as to the social, economic, political and psycho-physiological implications of this drug. We intend to study the cultural meanings, the institutional matrix, and the psychological and psychiatric effects of Qat under actual conditions of use. The study will employ clinical, and psychiatric techniques, and the use of video taping, coupled with more traditional methods of Anthropology. The results should provide some of the first depth data on the Yemeni culture in addition to illuminating the theoretical issues related to institutionalized drug use, and the practical problems which may be faced by the Yemenis as a result of extensive Qat use in their country.